Abstract: Optical microresonator platforms are provided comprising a substrate having a surface, a plurality of SiO2 pillars, and a plurality of SiO2 whispering gallery mode (WGM) optical microresonators, each SiO2 pillar extending from the surface of the substrate and terminating in a corresponding SiO2 WGM optical microresonator of the plurality of SiO2 WGM optical microresonators, wherein the substrate, the plurality of SiO2 pillars and the plurality of SiO2 WGM optical microresonators form a monolithic structure, and further wherein the substrate is substantially transparent to visible light. The substrate may be a SiO2 substrate and the SiO2 WGM optical microresonator may be a SiO2 optical microtoroid.

Abstract: A method comprises exposing the surface of an optical microcavity characterized by at least one resonance frequency to a sample such that a single particle or molecule from the sample adsorbs onto the surface of the microcavity; evanescently coupling a probe laser beam into the microcavity, the wavelength of the probe laser beam substantially matching the at least one resonance frequency; illuminating the surface of the microcavity with a free space pump light beam and moving the focal spot of the free space pump light beam such that the focal spot substantially overlaps with the single particle/molecule; and detecting light from the probe laser beam. The wavelength of the free space pump light beam generates sufficient heat via energy absorbed by the single particle/molecule to induce a shift in the at least one resonance frequency, thereby providing a change in an optical characteristic of the detected light.

Abstract: Methods and apparatuses for resonance tuning of microcavities are provided. An apparatus comprises a whispering gallery mode optical microcavity characterized by at least one resonance frequency; optical components configured to evanescently couple a probe laser beam into the microcavity; an absorber element in thermal contact with the microcavity; and optical components configured to illuminate the absorber element with a free space pump light beam, wherein the absorber element is configured to absorb energy from the free space pump light beam, thereby generating heat, and to transfer the heat to the microcavity, thereby inducing a shift in the at least one resonance frequency. The absorber element may be configured as a pillar forming an interfacial region with the microcavity at one of the ends of the pillar. The surface of the microcavity may be substantially free of a coating material.

Abstract: Methods and apparatuses for single particle and single molecule spectroscopy are provided.

Abstract: Methods and apparatuses for resonance tuning of microcavities are provided. An apparatus comprises a whispering gallery mode optical microcavity characterized by at least one resonance frequency; optical components configured to evanescently couple a probe laser beam into the microcavity; an absorber element in thermal contact with the microcavity; and optical components configured to illuminate the absorber element with a free space pump light beam, wherein the absorber element is configured to absorb energy from the free space pump light beam, thereby generating heat, and to transfer the heat to the microcavity, thereby inducing a shift in the at least one resonance frequency. The absorber element may be configured as a pillar forming an interfacial region with the microcavity at one of the ends of the pillar. The surface of the microcavity may be substantially free of a coating material.